Braking mechanism



w. E. PARKES 2,211,025 BRAKI'NG MECHANISM Filed Apr-i1 2a, 1939 5sheets-sheet 2 A ug.' 13, 1940.

l 94118.13,V 1940. w E. PARKEsL 2.211.025

MAKING MEcHAmsM l FiledApril 2s, 195s 5 sheets-sneet-'s -w. E. PARKESMAKING MECHANISM Filed April 2s, I1939 Aug. 13, 1940.

5 Sheets-Sheet 4 Aug- 13, 1940 w. E. PARKEs 2.211,025

BRAKING MCHANISM Filed April '28, 1939 5 sheets-sheet 5 lPatente-cl Aug.13, 1940 UNITED STATES Niiarlrrr OFFICE BEARING MEcnANIsM Walter E.Parkes, Norwood, Ohio Application April 2s, i939, serial 10.270535 A soClaims. (C1. 18s-3) means for the associator so that the powerapplication upon the independent braking mechanisms may be adjusted, forinstance, to relate or equalize their braking effects, whereby, forinstance, trailers or towed vehicles whose brakes have different brakecapacities or actuators may be substituted for each other for connectionwith a given tractor or towing vehicle, or tractors or towing vehicles,and trailers or towed vehicles may be readily intercbanged, and thebraking mechanisms on connected vehicles be readily equalized orrelated; and, further, to provide novelA operating means for the brakingmechanism'.l

It is the object of my invention, further, to

provide novel connecting means in braking,

mechanism to connect parts of the braking mechanism located on differenttrackless vehicles; further, t o provide novel means for counteractingthe detrimental results which would otherwise be present upon abreakaway of a trailer or towed vehicle from a tractor or towing imvehicle, whereby upon such breakaway the brakes upon the trailer ortowed vehicle are automatically applied; further, to provide' novelymeans whereby such application of brakes upon a breakaway is maintained;further, to provide novel control means for 4the latter; further, toprovide novel means for disconnecting parts of braking mechanismrespectively on `normally connected trackless vehicles in novel mannerwhereby separationbetween the vehicles may take place 'and theconnecting parts of braking mechanism on the respective vehicles may bere-arranged on the respective vehicles; further, to arrange suchconnecting parts for independent brake application upon the respectivevehicles; Y is'furthen to provide novel means between the as and fromthe drawing, in which, latter :f

Fig. 1 is a plan view of my improved braking mechanism in associatedrelation respectively on a tractor, truck or propelling Vehicle,hereinafter also referred to as a towing vehicle, and a propelledvehicle or trailer, hereinafter, also referred to as a towed vehicle,partly diagrammatic, with parts of the vehicles removed and partsbroken' away. The vehicles are shown as trackless vehicles. v

Fig. 2 is a diagrammatic representation of a hand valve, a controlvalve, relay valves and a` power actuator in associated relations, andpartly 'broken away, the valves being shown in axial section, and theconduit vconnections being shown partly in dotted lines, the poweractuator being also known as a power cylinder or booster cylinder.

Fig. 3 is a vertical section, taken on the line 3-3 of Fig. 1, andpartly broken away, showing a compensating ixture,- to which anactuating part of the brake mechanism for the towed vehicle (shown indotted lines), is arrangedto be applied when the towed vehicle isintentionally disconnected from the towing vehicle.

Fig. 4 is a diagrammatic representation of my improved brakingmechanism, partly broken away, and partly shown in dotted lines.

Fig. 5 is a plan View of the associating'mechf anism for associatingaplurality of brake mechciating mechanism, taken on the line 8 8 of Fig.

5,and partly broken away.

Fig. 9v is a vertical section of the breakaway mechanism, taken on theline 9-9 of Fig. 1, and partly broken away.

Figs. 10 and 11 are cross sections of the latter,

taken respectively inthe planes of the lines l Ill-I0 and H-,Il of Fig.9.

Fig. -12 isa plan view showing a modification of the connecting meansbetween av towing vehicle and a towed vehicle, partly broken away, andshowing the actuating means for the brake mechanism on the towed vehiclemounted on the towed vehicle in Iull lines, and mounted on the towingvehicle in association with the compensating fixture in dotted lines;and,

Fig. 13 is a vertical section of the same, taken on the line |3|3 ofFig. 12, and partly broken away.

A towing vehicle 2| comprises front wheels 22 and rear wheels 23respectively provided with brakes 24, having usual brake cylinders 25respectively arranged to be actuated by suitable fluid for applying thebrakes (Fig. 1). A towell vehicle 21 is connected with the towingvehicle and has wheels 28, 29, provided `with brakes 39, respectivelyhaving brake cylinders 3| for applying the brakes. The brakingmechanismsl respectively on the towing vehicle and on the towed vehicleare each self-contained to permit independent brake application on eachof said vehicles. Conduits 34, 35 connect with the respective brakecylinders 25 of the brakes for the front wheels and the rear vheels ofthe towing vehicle, and are interconnected by a conduit 36. Conduits 31,38 connect with the respective brake cylinders on the towed vehicle andhave a conduit 39 connected therewith.

Conduits 4|, 42 connect respectively with the conduits on the towingvehicle and the towed vehicle, the former by a connection 43, and thelatter by a breakaway mechanism 44, hereinafter described (Figs. 1, 4and 5). These conduits form fluid passages for suitable brake actuation,and in the present. exemplification contain a suitable braking liquid,such asI oil and other ingredients well known in the art, to whichpressure is applied for applying the brakes, relief of pressure thereonreleasing the brakes. Fluid operating units 45, 46, such as so-calledmaster cylinders or pressure cylinders, connect with the respectiveconduits 4|, 42, and have an associator coacting therewith for brakeactuation and release of the brakes'on the towing vehicle and on thetowed vehicle.

Each of the fluid operating units or master cylinders 45, 46, (Fig. 7)preferably comprises a pressure cylinder53, in which there is a piston54 provided with a flexible cup washer 55 at its inner end, bearingagainst a flange 56 of the piston provided withapertures 51, closed bysaid washer when the piston moves inwardly for applying pressure andallowing passage of the pressure liquid therethrough when the pistonmoves outwardly for release of the brakes.

. The outer end of the piston has a radially extending flange 58,limiting outward movement of an annular packing ring 59, between whichand an annular flange 56 at the inner end of the piston there is a space68'. A limiting flange 6| releasably held in an annular rabbet`62 in theouter endof the cylinder by a spring ring 6 3, retains the piston in thecylinder. The other end of the cylinder is provided with a plug 64,threaded into said other end, the conduit 42 being operatively connectedwith said plug for communlcating with said cylinder. A reservoir 61 lslocated above the cylinder, there being holes 68, 69 in the wall 10between said reservoir and the cylinder, the hole 68 communicating withthe vspace 68, and the hole 69 communicating with the space 1| in saidcylinder between its pistonand the plug 64. A spring 12 between saidplug and the piston normally retracts the piston and holds the washer to,the piston. AThe reservoir has a filler opening 13 in which a closingplug 14 is threaded. I

The cylinder 53 is normally lled with the pressure applying liquid,which readily passes to and from the reservoir through the holes 68, 69during the initial portion of the brake applying movement of the pistonin the direction of the 'arrow a, and maintains the braking mechanismcommunicating therewith in operative condition without supply of. fluidor fluid connection with an outside source, and making each brakingsystem self-contained. The hole 69 is covered by the cup washer 55,,thereby preventing return flow of. the liquid to the reservoir duringadvancing movement of the piston for applying pressure to the liquid inthe cylinder in advance of the piston, the conduits connected therewith,and the brake cylinders on the vehicle to apply the brakes. When thebrake applying force is released the piston is retracted, aided by theaction of the spring 12 for releasing the brakes.

It is important in a liquid pressure or hydraulic system of thischaracter that the liquid be kept free of air and other gases which arecompressible and would prevent the transmission of pressure from thepressure cylinder to the brake cylinder and result in consequent brakefailure. The reservoir and passages between it and the pressure cylinderinsure that the pressure cylinder shall always be properly filled withthe pressure liquid and permit retraction of excess liquid there may bein the cylinder.

. One of the fluid operating units is provided for the brake mechanismon the towing vehicle and one of the same is provided for the brakemechanism on the towed vehicle, and the associator 5| is provided forcombined operations of these fluid operating units so as to impart brakeapplication simultaneously to the respective brake mechanisms forsimilar and simultaneous b operations of the brakes on both the vehiclesin order that each vehicle may be independently stopped without unduepressure or'dragging between the vehicles. y

The assoclator'exempllfied (Figs. 4, 5, 6, 7 and 8) comprises anoperating rod 11 having a joint 18 therein and reciprocable in a bearing19 on a support 68, shown as a bracket secured to the frame or chassis8| of the vehicle by bolts and nuts 82, and comprising a shelf 83. Across bar 85, which may be termed an equalizer bar, has pivot connection66 with the operating rod 11. Piston rods 81, 88 have pivot connections89, 96 with the cross bar. Ihe inner ends of each of these piston rodsis seated in` a seat 9| at the bottom of a socket 92 extending inwardlyinto the piston and flaring outwardly toward its mouth to accommodatetilting movements of the piston rod. A shield 93 is received over theouter end of the cylinder and is provided with a central hole in whichthe piston rod is located, the shield being, for instance, of rubber,and making close connections with the piston rod and the cylinder forshielding the mechanism therein from exterior dust,l dirt and moisture.

` The fluid operating units are normally located at the respective sidesof the operating rod and parallel therewith and equidistant therefrom.Assuming' that the cylinders of the fluid operating units are of equaldiameters for brake application, this relation is normally satisfactorywhere the braking mechanism on the towing vehicle and the brakingmechanism o'n the towed vehicle are of substantially equalv capacitiesgaged by the respective weights of the towing and towed vehicles, forequal brake application on both. I have found in practice, however. thatit is desirable to connect various towed vehicles selectively with giventowing vehicles and to ingreatest economy in the carrying equipment 'andfor steadiness of. employment of the drivers andv attendants. The towingvehicle mayA be engine equipped or be one of a train of `vehiclesfollowed by another vehicle in the train.

The braking capacity of various towing vehicles and the various towedvehicles varies so that it may be desirable for efliciency to connect atowing vehicle having one braking capacity with a towed vehicle havinganother braking capacity, which may be either greater or less than thebraking capacity of the towing vehicle. I provide means therefore forproperly equalizing or relating the associator between the uid operatingunits for the respectivebraking mechanisms of the towing vehicle and thetowed -vehicle in order to compensate for this varying conditionbetween-such braking mechanisms. An adjustment is provided between theoperating rod andA the fluid operating units whereby te apply a greateroperating pressure to one than to the' t fluid operating units are shownvin fixed relation to each other, being rigidly secured to a support 91,shown as a channel piece, the cylinders of the fluid operating units,being fixed tothe flanges 98, 99 of the channel piece by bolts |00, |0|.

The operating rod is provided with a fork |03, the tines of which arelocated at the respective sides of the cross bar, and are pivoted onsleeves |04 at the respective sides of the cross bar. The proximate endsof the sleeves impinge upon the respective sides of the walls of a slot|05 in the cross bar, the outer ends of the sleeves being provided withflanges |06, and the sleeves and cross end of the assembly. Thisassembly readily tiltsl,

in the pivot holes |09 in the tines of the fork |03 in which the sleevesform pivots for pivoting the cross bar ,at any point -in the length ofthe slot, constituting the respective ends or arms of the cross bar ofvarying lengths at the respective sides of its pivot. The piston rod81'is provided with a fork the tines of which are located attherespective sides of the cross bar and connected therewith by a pivot pin||2. The piston rod 88 is provided with a fork H3, the tines of whichare located at the respective sides of the cross bar-and connectedtherewith by a pivot pin H4.v Cotter pins 'H5 hold the pivot lwhich thefluid operating units .are secured, is

adjustable laterally with 'relation to the operating rod and the bearingin which it is located to accommodatefor any adjustment between thecross bar 85 and the operating. rod, being adjustable on its supportingbracket, asby providing the channel piece with cross slots H6, throughwhich clamp bolts pass, the clamp bolts being-threaded into the bracket,for clamping the channel piece in laterally adjusted positions, washersI I8 being located between the heads of the bolts and said channelpiece.

vIf adjustment be' made so that there is unequal distance between thejointed connection of the operating rod with the cross bar and therespective jointed connections between the cross bar and the pistonrods, unequal forces are ap'- plied to the respective piston rods forapplying a greater or a less pressure to the braking mechanismsrespectively for the towing vehicle and the towed vehicle to compensatefor the varyingcapacities of the brakes respectively on the towingvehicle and the towed vehicle, to equalize the braking effect on thesame, respectively..

The operating rod Ti may be manually operated or may be operated bypower or selectively by both said means. I have preferred toso relatethe parts that there shall be only limited relative movement between thepistons in the cylinders of lthe fluid operating units, as only limitedrelative movement is required between the same to compensate for thevarying braking capacities on the different towed vehicles and differenttowing vehicles which may be associated. I employ such capacity forlimited movement as a safety feature to avoid failure of brakelactuation simultaneously in all of the brakes, such limited movement inthe present exemplification being obtained by limiting the tiltingmovement between the cross bar and the actuating rod and selectivelybetween the cross bar andthe pistons, 'obtained by providing the crossbar 'and the actuating rod withshoulder's |21, |22 normally spaced by aspace |23, and the cross bar and the piston with shoulders |24, |25,normally spaced by a limiting space |26, permitting desired tiltingmovements of the cross bar on the actuating rod and with relation to thepistons for brakeequalization, but preventing excess tllting movement ofthe cross bar on the operating rod to maintain active relation betweenthe operating rod and the piston rods of the respective'fluid operatedunits. This linsures independent actuation of thepiston rods in case ofdisarrangement or leakage in one of the braking mechanisms, toward whichthe cross bar would then tilt, limited by contact between the shoulders,so as to retainA active connection with and apply braking force to theother braking mechanism, which yis still in order.

in order to insure stoppage of the connected vehicles.

By these means brake application on either the towing Suitable means areprovided for operating the.

operating rod. These means may be operated either manually or by power,and the power' means may be either mechanical or may be fluid actuatedby -normally balancedA controls, unbalanced for actuation by a lowerpressure, for instance, vacuum, controlled or actuated by a highe'r,pressure, for instance, atmosphere; or by a lower pressure, forinstance, vacuum or atmosphere controlled or actuated Vby a higherpressure higher than atmosphere suitably obtained; or

by Vsuitable combinations of the same, suitablyl obtained; but I preferto show vsuch power actuation by means of vacuum created by the sulctionoiA an engine on the towing vehicle, controlled -by atmosphere which isintroduced for unbalancing the pressure at the respective sides of apiston.

I prefer to employ manually actuated means for unbalancing control, soarranged as to effect brake application in case of failure, wholly orpartial, of the power actuating means. Thus a pedal lever |3| is pivotedto the frame 8| of the towing vehicle on a pivot |32, a spring |33between the pedal and the frame normally retracting the pedal. (Figs. 1,4, 5 and 6.)

A rod |34 has pivotal connection |35 with the pedal and has slideconnection |36 with a control valve |31. The rod is arranged to move thecontrol valve in applying the brakes. It -has a valve |38 which servesas a stop, which coacts-v with a valve seat |39, which serves asacoacting stop, to move the control valve. A rod |4| is fixed to thecasing of the control valve by a threaded connection |42, and isprovided with a fork |43 having jointing connection |44 with a lever |45pivoted by a pivot |46 in a fork |41 secured to the I frame 8| of thetowing vehicle in such manner,

as to hold the lever in horizontal position. A rod |48 has a fork |49which'has jointing connection |50 with said lever, and is provided witha. fork |5| which has jointing connection with a fork |52 and a lever|53 by a pivot pin |54 in the tines of said forks and in said lever. Thefork |52 is fixed to the operating rod 11 by threaded connection |55.

The lever |53 passes through an opening |56 in the channel piece 91 anda slot |51 in the shelf It is pivoted by a pin |58 to bearing lugs |59extending from said shelf and located in the opening |56. The operatingrod 11 is slidable endwise in the bearing 19 extending from the shelf83, as by being fixed thereto by a bolt |60. and extending through anopening 6| in the channel piece. The openings |56, |6| permit lateraladjustments of the channel piece on the shelf without disturbance of theoperating rod or its mounting means, or disturbing axial alinement-ofthe parts, when laterally adjusting the fluid operating units.

The power connection with the operating rod isobtained by means of apower actuator |65. The power actuator may be operated mechanically orby compressed air or other fluid. It is shown as a booster cylinderwhich comprises a cylinder |66 and a piston |61 therein, from which apiston rod |69 extends and has pivotal connection |69 with the lever|53. The cylinder of the power actuator is provided with a lug |1| inwhich there is a pivot pin |12, the pivot pin being also mounted in aforked bracket |13, depending from the shelf at one end of said shelf.The power actuator maintains its alinement in a vertical plane with itsactuated parts upon adjustment oi' the channel piece 91.

'I'he piston |61 is normally in retracted position. (Figs. 4 and 6.) Inthe present. exemplification the actuating agent is vacuum, created by'suction from the vehicle engine and exhausting air from the cylinder atone side .of the piston through a conduit |16, which at one end hasconnection through a port |11 with the cylinder, and

at its other end has connection through a port |18, with the intake |19ofthe engine, there being a check valve in this conduit toV maintain thevacuum in the sectionof the conduit "connecting with the power actuator.'I'he piston in the power actuator is normally in balanced condition inits cylinder with vacuum at both sides thereof, being normally moved toone end of the cylinder by means of a spring |8| between the frame andthe lever |53 for retracting the piston. A bellows shield |82 isnormally located about the piston rod.

In order to create vacuum at the retracting side of the piston, air isdrawn therefrom through a` branch passage including a conduit |85operatively connecting with the vacuum conduit |16 at |86, a relay valve|81, a pipe |88 between said relay valve and a second relay valve |89,and a conduit |90, one end of which has communication with the secondrelay valve at one end thereof, the other end thereof communicating witha port |9| at said side of the piston ln the cylinder of the poweractuator.

The relay valve |61- (Figs. 2 and 4)V comprises a casing |93, in whichthere is an outlet port |94, a chamber |95, a chamber |96, between whichchambers there is a passage |91, having valve seats |98, |99 at itsrespective ends, with which respectively valves 200, 20| of a two-wayvalve 202 coact. A diaphragm 203 is ilxed between the casing and a head204 thereof secured to the casing and clamping the diaphragm between itand the casing. The double acting valve 202 is secured to the diaphragmby a connection 205, and the diaphragm is normally urged to seat thevalve 20| of the double acting valve by means of a spring 206 betweenthe diaphragm and the casing head. A passage 201 in the casing communi--cates with the cavity |96 and connectsfwith a pipe 208 communicatingwith the atmosphere Y through a cleaner 209, secured to said pipe. The

casing further hasa passage 2| therein, communicating with the passage|91 and with the pipe |88 connecting the casings of said relay valves.'I'he cap204 is provided with a port 2|2.

The relay valve |89 comprises a casing 2| 6 in which there is a cavity2|1 and a cavity 2|8 connected by a passage 2|9, and having valve seats220,4 22|, at the respective ends of said passage. A passage 222connects the passage 2|9 with a port 223 in said casing. A passage 224connects the cavity 2|1 with the other end of the pipe |88. A diaphragm225 closes the outer end of the cavity 2|8, the margin of the diaphragmbeing clamped between the casing and a cap 226 provided with a port 221.I'here is a double acting valve 226, comprising valves 229, 230,coacting with the respective seats 220, 22|. The double acting valve issecured to the diaphragm by a connection 23|. A spring 232 between thecap and the diaphragm acts on the diaphragm to normally close the valve230. A passage 233 in the casing communicates with the cavity 2|8 and apipe 234, which has an air cleaner 235 on its outer end.

Vacuum is normally created at the spring actuated side in the piston ofthe power actuator |65 (Figs. 2, 4 and 6), through the conduit |90, theport 223, the passage 222, the passage 2| 9, the valve seat 220,normally open, the cavity 2|1, the passage 224 in the relay valve |89,the pipe |88, the passage 2| I, the passage |91, the valve seat |98, thecavity |95, the port |94, and the conduit |85 connecting with theconduit |16 leading to the intake manifold of the engine.

The control valve |31 includes a casing 24|, in which there is a cavity242, a passage 243 connecting therewith, and valve seats 244, |39 at therespective ends of the passage 243, arranged yto communicate with saidcavity 242 at one end thereof, the other end of said passagecommunicating with the cavity 245 oi an air cleaner 246, thewall of thiscavity being substantial and having threaded'connection 241 with thecasinget y one end thereof, and the rod |4| having threaded the rod |34,for normally closing the valve seat 244. The casing is provided with aport 25| communicating with the cavity 242. The casing is also providedwith a port 252 communicating with the passage 243. A conduit 253communicates with the port 25| and with the vacuum conduit |16 at 254,and a conduit 255 communicates with the po'rt 262 and with the port 221of the relay valve |69.

The diaphragm 225 of the relay valve |99 is normally collapsed byhaving4 atmospheric pressure thereon through'the port 221, (Figs. 2,4and 6) the conduit 255, the port 252, the passage 243, and through thevalve seat |39 with the air cleaner 246. When the pedal |3| is actuated,pull is 'exerted on the rod |34 for closing the4 valve seat |39, andhaving the valve |38l act thereon as a pulling agent to move the controlvalve in the direction of pull and exerting pulling i'orce upon the rods|4|, |48, for manually actuating the operating rod 11 by its connectionstherewith. Normally, however, the main duty of actuating the operatingrod is relieved by the power actuator, for the reason that when thedouble acting valve 248 is thus actuated, the valve |38 thereof closesthe valve seat |39, and thereby closes communication between the aircleaner 246 and a cavity 258 in the relay valve |86, between the cap 226and the diaphragm 225 thereof, and opens the-valve seat 244 forconnecting said cavity with the conduit 253 for exhausting air from thecavity 258, and thereby raising the diaphragm 225 and unseating thevalve 230 and closing the valve 229 and opening the POrt |9| in thepower actuator to atmosphere through the cleaner 235, the pipe 234, thepassage 233', the cavity ,2|8, the valve seat 22|, the passages 2|9,222. the port 223, the conduit |90 and the port |9|, for collapsing thebalanced condition of the piston |61 and causing actuation of saidpiston by the force of the vacuum received through the conduit |16 andactuating the lever |53, having operative connection with the operatingrod 11 for power actuation ofthe latter. It, however,I

this power actuation should for any reason fail,

' the manual operation of said operating rod is still eiective.

Unbalanced condition of the piston in the power actuator may also beobtained by means oi' a hand valve 26|, for hand control of poweractuation of thel brakes independent oi' the pedal. The hand valvecomprises a casing 262, having a valve seat 263, in which there is avalve plug 264, arranged to be operated by a handle 265 on the valvestem 268, the valve being held to its seat by a suitable -gland261'threadecbto-the valve casing and compressing a suitable spring 268be-4 tween said gland and the plug. The valve casing is provided with aport 269 and a port 216.

A conduit 21| connects the port 266 with the vacuum conduit |16 by ajoint 212, and a conduit 213 connects the port 216 with the port 2|2 ofthe relay valve |81.v The valve plug has a.

When the hand valve is opened, the passage in its plugconnects the ports269, 210 and opens vacuum communication between the manifold |19 and theport 2|2 of the relay valve |81 acting on the diaphragm 203 thereof toopen the valve'seat |99 and close the valve seat |98, and admitting airthrough the air cleanerl 209, ,the

valve seat |99 in the relay valve |81, the valve seat 220 inthe relayvalve |89, and the conduit |90 communicating with the port |9| of thepower actuator for collapsing the balanced condition of the pistontherein and causing operation of the piston by vacuum through the port|11 and thereby operating the lever |53 for operating theoperating rod11 by power.

In the present exemplication of my invention, the. brakes are hydraulicbrakes. In such' mechanism it is important that an ample amount ofliquid be maintained in the braking system, and that no air or other gasbe admitted into the system, so that the moving'force of the liquid beat all times effective in brake application, in each brakingr system. Itis also important that no severance or leakage take place in either orany braking system which would decrease the amount of braking liquid orthe solidity of the same.

These objectives are accomplished in my improved device, and in it thebraking system for the towling vehicle and the braking system for thetowed vehicle are separated from each other so as to maintain the fullamount of braking liquid in each and to avoid the transference ofbraking liquid from one to the other.

I provide brake operating connecting mechanism between the towingvehicle and the towed vehicle for operating the brake operating means onthe towed vehicle by brakeactuating means on the towing vehicle, andprovide separate fluid devices for said brake operating connectingmechanism separated from the fluid brake operating means on the towingvehicle and the iiuid'brake ,operating means on the towed vehicle, ifsuch brake operating means be fluid actuated, so that each of the latterremains intact upon separa- Ation between the towing vehicle and thetowed vehicle, whether such separation be intentional as byinterchangebetween towing'and towed vehicles, or be accidental, as in the case of abreakaway between said vehicles.

The brake operating connecting mechanism between the towing vehicle andthe towed vehi- ,cle comprises a movable member on the towed vehicle forbrake actuation on the towed vehicle, and a connection between a brakeactuating part on the towed vehicle and the towing vehicle, soconstructed that when a breakaway between the towed vehicle and thetowing vehicle takes place, the brakes on the towed vehicle are appliedby said connection. This connection may be apartable connection, and ifpartable. brake application on the towed vehicle takes place prior tosuch parting. Said connection is normally idle.

the hitch between the vehicles forming the travel connection between thevehicles. VWhen such providedl with a seat 284A for one end of a rod285. A plug 288 is threaded in one end of the cylinder and has a port281 therein, to which the delivering end of the conduit 42 is suitablyse- Ocured to communicate with the interior of the cylinden A cup washer288 coacts with the piston, a spring 289 between the cup Washer and theplug urging the piston outwardly toward the rod 285. Alimiting ring 280held in a rabbet 29| in said end by a spring ring 292, holds the pistonin the cylinder.

A uid operating unit 285 is provided on the towed vehicle and isactuated by the fluid actu- (Figs. 1, 4 and 9.) operating unit isexempliiied as a So-called master cylinder, and is similar to the fluidoperating units or master cylinders 45, 48 on the towing vehicle, itsrespective parts being designated by similar reference numerals raisedto the series 600. It is normally operated by the uid actuated unit 28|,by having the rod 285 thereof coact with the piston 854, the end of therod being seated in the recess 89| in said piston.

The conduit 39 for the brake mechanism on the towed vehicle is suitablyconnected with the plug 864 for communicating with the inside of thecylinder 653. The fluid operating unit 288 and the fiuid actuated unit28| as shown form part of the breakaway mechanism 44.

The breakaway mechanism preferably includes means whereby to maintainthe brakes on the towed vehicle applied after application thereof by abreakaway, and means are also provided for reassuming control of thebraking mechanism on the towed vehicle after a breakaway. Means arefurther provided for intentional separation between the brakingmechanism on the towing vehicle and the braking mechanism on the towedvehicle, and to establish such connection between different towingvehicles and towed vehicles; and means are also provided whereby thebrake operating connecting mechanism may be separated from the towedvehicle and connected with a compensating means for the brake mechanismon the towing vehicle, so as to maintain normal uid pressure in thelatter, in order that the operation of the braking mechanism for thetowing vehicle may not be substantially interfered with upon suchseparation; and means` are further provided for independent actuation ofthe braking mechanism o n the towed vehicle after accidental orintentional separation between the towed vehicle and the towing vehicle.l

In a breakaway of the towed vehicle, excess strain is placed upon theconduit 42, and the conduit connection between the towing vehicle andthe towed vehicle is severed in the exemplification of the inventionshown in Figs. 1 to 11 inclusive. This conduit connection which may be aflexible hose, in the preferred form of the invention hereinexemplified, serves as a fluid passage connection for the brake applyingfluid between the towed vehicle and the towing vehicle; for normal brakeoperation from the towed vehicle, and also as a tension connectionbetween the vehicles to operate the brake operating means on the towedvehicle upo'n a breakaway between the vehicles prior to parting ot saidtension connection. p

In the present exempliiication there is a slide 288, shown substantiallyU-shaped in cross section. (Figs. 9, 10 and 11.) 'Ihe fluid actuatedunit 28| is secured to the slide by means of pins 291 in mating holes288 in the side walls 288' of the slide and holes 300 in lugs 30| of thecylinder This uid 282. These pins are connected by a handle 302 rigidtherewith for combined movements of the pins when connecting theactuated unit 28| with the slide or disassociating it therefrom. Cotterpins 303 in the pins 281 normally hold the pins in the holes.

The fluid operating unit 288 is also secured to the slide, as by meansof bolts 384, passing through holes 305 in one of the side walls of theslide and into threaded holes 306 in lugs 301 of the cylinder 853. Thelugs on the cylinders 282 and 853 are positioned laterally between theside walls of the slide so as to position the axes of said cylinders inalignment. 'I'he rod 285 is operatively located between the pistons insaid cylinders in alinement therewith.

The slide 288 is slidable lengthwise in a guide 3| l, Vsecured to theframe of the towed vehicle, as by being located between bars 3|2. 3|3of\said frame. Studs 3|4 pass through said bars and through alignedholes 3|8, 3|8`in lugs 3|1, 3|8 extending from the side walls 3|8, 320of the guide, sleeves 32|, 322 being located between said lugs and saidbars vfor laterally positioning the guide, and nuts 323, 324 beingthreaded over the threaded ends of the studs for clamping the partstogether and rigidly positioning the guide. The slide is provided withextensions 321, 328 at its respective ends, the studs being locatedabove said extensions for holding the slide downwardly in the guide andpermitting endwise movement of the slide in the guide, such endwisemovement being limited by contact of the respective ends 329, 330 of theside walls oi the slide with said studs.

The side flanges ofthe guide 3|| are extended upwardly as lugs 33| at apoint intermediate of their ends to provide bearings 332, 333 for across-shaft 334. Cams 338 are secured to the cross-shaft, as bypins 338held in suitable mating holes in said cams and in the cross-shaft.Spacing collars 331 are located'between said cams and the side walls ofthe guide. These cams have cam faces 338 arranged to engage the slidefor holding the slide in actuated position. The c0- acting faces on thecams and slide are preferably so constructed as to lock the slide inactuated position on a breakaway to maintain the parts in actuatedrelation. An arm 34| is xed to the cross-shaft 334. A spring 342 havingconnections 338. 340 at its respective ends with this arm and the guide,normally urgesthe cam into cam engaging relation with'the slide. The camshaft 334 is arranged to coact with the rod 288 when the slide is inabnormal position, and is shown received -through a slot 343 in anenlargement 344 of the rod. (Figs. 9 and l1.) The rod is normally movedendwise in brakev releasing direction by the spring 812 in the cylinder883, in which relation the end wall 348 of the slot engages thecross-shaft for idle relation of the parts.

When the brakes on the towed vehicle are applied normally, the piston283 is moved toward the outer end of the cylinder 282 for moving the rodendwise, with the walls of the slot therein moving with relation to thecross-shaft. the cross-shaft and the cams thereon remaining stationaryduring normal operation 'of the`device, and the slide 288 being movedendwise by the spring ,812 ooacting with the cross-shaft 334. for'contact of the shoulder 328 on the slide with the stud 3|4 adjacentthereto. Such movement may be amplified by a spring 348, one end ofwhich is attached to a pin 341 secured to the u slide and passingthrough a slot 346 in the guide, the other end of the spring beingattached to a pin 349 on the guide. y

Upon accidental parting between the towed vehicle andthe towing vehicle,as upon a breakaway, tension -is exerted upon'the conduit 42, pullingupon the same, and by means of its connection with the fluid actuatedunit 28|, this unit, the slide 296 to which it is attached,

and the fluid operating unit '295 also attached.

to the slide,l are pulled endwise, whilst the rod 285 is held stationarywith relation to the towed vehicle by reason of contact of the end wall345 of its slot 343 with the cross-shaft 334, in the presentexempliiication, so that there is endwise movement of the cylinder 653.of the fluid operating unit', whilst the rod 285 is held endwisestationary with the towed vehicle, thereby actvthe conduit 42, theconduit connection will naturally part, but'the pulling strain thereonupon the brake applying mechanism on the towed vehicle will before suchparting have been sucient to apply the brakes on the towed vehicle. Suchpulling action upon the cylinder 282 has also moved the slide 296lengthwise in its guide, whereby the bottom oi the slide is moved underthe cams, which prevent retraction Aof the slide and maintain the brakeapplying means in brake applying position. 'After such full emergencybrake applicationthere is preferably still some of the space 350 leftbetween the shoulder 330 on the slide and the stud 3|4 adjacenttheretoto insure such full emergency brake application.

The tension connection 42 between the towing vehicle and the towedvehicle parts upon further separation between the vehicles after fullbrake application of the towed vehicle, and the holding mechanism,instanced as the cams, holds the brake applying means in brake applyingposition until the parts are again intentionally unlocked. The towedvehicle is therefore iin-l mediately stopped upon a breakaway, so asv toavoid accident, and the stopping of vthe towed vehicle' continues untilintentional or manual control thereover is again assumed.

'I'he manual control is exemplified as alever 353, (Figs.l, 4 and 9),pivoted. on a pin 354, lo-

cated in bearings355 of -a fork 356, fixed to the frame of the towingvehicle, as on a cross-piece 351 thereof The lever is provided with ahandle 358. A supplemental lever 360 is pivoted on the main lever 353bya pivot 36|, and has a handle 362 thereon, normally spaced from but inadjacency to the handle 356. A flexible connection 363, as a cable, has-one end thereof secured to :a lug 364 on the lever 360, and passesabout 'the pivot pin 354, and is connected with the outer end of theoperating arm'34l of thecamshaft 334, preferably through theinterventionvof av spring 365, the respective en'ds of which are vsecuredrespectively to said operating arm 34| vand to said flexible connection363. The lever 353 is operatively connected with the slide, as by aflexible connection 366, which may be -a cable, the respective-ends ofwhichy are secured to said lever and to said slide, for instance, asshown respectively at 361 and 368. t

The spring 342 extending from the operating arm 34| atone side thereofto normally hold the cams in operative contact with the slide, is aspring of sufficient capacity to urge the cams into engagement with theslide and to insure such engagement and cam action when the slide hasbeen pulled lengthwise by a breakaway and to prevent retraction of saidslide until the cam hasbeen intentionally lor manually released.

Such release is effected by grasping the handles 358, 362, and urgingthe handle 362 toward the handle 358 on the pivot of theformer, andthereby pulling upon the ilexible connection 363 for pulling upon theoperating arm 34| in release direction, cushioned by the spring 365,when the latter is employed, and thereby placing the slide 296 undercontrol of the lever 353 for manipulating the braking mechanism on thetowed vehicle independently of. any connection there might have beenwith the braking mechanism on the towing vehicle and constituting anindependent brake actuating means on the.

towed vehicle. Such independent brake control of the towed vehicle isalso effective upon the braking mechanism of the towed vehiclethrough-out usual manipulations of the towed vehicle,.for instance, inloading and unloading the same, in connecting the same with its selectedtowing vehicle and other manipulations of the towed vehicle which may bedesired for usual operations thereof. Such manual manipulations are alsoeffective after a breakaway for intentional movement of the towedvehicle or its reconnection with a towing vehicle.' operations are' veryfrequent and take place at each loading and unloading of the towedvehicle,

so that such manual control is under continual test to insure that thebreakaway emergency con-` -trol of the brakes is continuously eiective.

The spring 365 is preferably a stronger spring and is capableof-exerting mo're force than the spring 342, and issubordinate inmovementA to the spring 342 throughout the range of emer-l gency camapplication by the latter, by reason of having more idle space in itsconnection with `rthe operating lever 353 than is in the connection ofthe springs 342 with the. guide 3H.

The spring 365 becomes preponderant over the spring 342 during servicemanipulation of the brakes on v the towed vehicle by the `lever 353, inthat 'it yields to manual strains on the flexible connec, tion 363 topermit controlled movements of the handle with relation to the handle356 and de'- Such sired movement of the lever 353 on its pivot 354. Whensuch service manipulationlias been completed, the handle .362 isreleased for placing the lever 34| under control of the spring 342 forvengaging' the cams 335 with the slide, tohold the slide in manipulatedposition for brake application.

It is often desirable to operate the towing vehicle with no towedvehicle attached, and I have 'provided means whereby this may be donewith the brake applying means on the towing vehicle vmaintained inoperative condition equal to its operative condition when a towedvehicle is attached. In brake applying 'means employing a uid for brakeoperation, on the towing vehicle, it

is desirable that the resistance of the 'fluid shall be' substantiallyequal, whether or not a towed.

vehicle is attached to the towing. vehicle, and I have thereforeprovided meansnwhereby there may be separation between the towed vehicleand the towing vehicle and the brake operating means between the same,and reacting means provided for tls.' brake applying means on the towingvehicle in substitution for the brakeV applying means on the towedvehicle in order that the brake applying means on the towing vehicle maycontinue their duties of brake application in the same manner after thetowed vehicle is removed.

In the present exempliilcation the iluid in that portion of the brakingmechanism between the towing vehicle and the towed vehicle acts on thepiston 283 in the fluid actuated unit with which the connecting conduit42 has iluid lconnection (Figs. 1, 3, 9 and 10.) This piston is providedwith the socket 284, in which the operating end of the actuating rod 285is normally located. I'his fluid actuated unit may be removed from thetowed vehicle and mounted on the towing vehicle in association with acushioning reacting device 310 on the towing vehicle, when it is desiredto rdisconnect the towing vehicle from the towed vehicle, and the brakeson the towed vehicle applied by the lever 353.

The cushioning reacting device exemplied comprises a supporting plate81| on the towing vehicle having a guide 312 secured thereto by boltsand nuts 313. This guide is provided with a channel 314 having sidewalls 315 and an end lug 316, which has a bearing 311. An adjusting rod318 is reciprocable endwise in this bearing. This rod is screw threadedand has an 'adjusting nut 319 and a jam nut 388 threaded thereon. Theouter end of the threaded rod has aV limiting shoulder 38| securedthereto, being shown as a j nut threaded over the rod and secured to therod by a pin 382. A spiral spring 383 is located about4 the rod and iscentered with relation to the rod and spaced therefrom by having itsrespective ends located about spacing bosses 384, 385 respectively onsaid lug and a washer 386. 'I'he inner end of the rod has an endformation 381, about which the wall of the socket 284 is located whenthe fluid actuated unit 28| is secured to the towing vehicle.

This fluid actuated unit is arranged to be moved bodily from the towedvehicle to the towing vehicle by removing the pins 281 by pulling on thehandle 382 for releasing the same from the towed vehicle and placing iton the towing vehicle in operative relation with the rod 318, as bylocating its lower portion with its lugs 38| in the channel 314, withthe holes 388 therein registering with companion holes 388 in therespective side walls 315, and inserting the pins 281 in said matingholes by pushing on its handle 382 and reinserting the cotter pins 383,for connecting the cylinder of the fluid actuated unit with the towingvehicle, the conduit 42 retain` ing its connection withsaid cylinder`for operating the piston 283 when 'the brakes on the towing vehicle areapplied by 'means of the equalizing device This application of thebrakes causes endwise movement of the piston 283, thereby actuating therod 318. resisted by the spring 383, in simulation of the resistance bythe braking mechanism on the towed vehicle when such fluid actuated unitis normally connected with the towed vehicle. Such resistance by thespring 383 is adjustable by adjusting theadjusting nut 318 and its iamnut 388. The brakes on the towing vehicle may now be applied with thefull assurance that the brake application shall be the same on thetowingr vehicle as when the towed vehicle was attached thereto. 'I'heresistance of this substitute device substantially equals the normalresistance of the braking mechanism on the towed vehicle for 4which ithas been substituted.

If it is desired to re-connect a towed vehicle with the towing vehicle,the brake mechanisms between the two are readily re-connected byremoving the fluid actuated unit 4from the towing vehicle andre-locating it on the towed vehicle, by the simple operation in thepresent exemplification oI removing the pins 281 from the towingvehicle, changing the fluid actuated unit from its channel on the towingvehicle to its slide on the towed vehicle, and reinserting the pinsthrough the mating holes 288, 388, with the end of the operating rod 285located in the socket 284 of the piston 283.

In the present exempliilcation the fluid operating units 45, 48 retaintheir connections with the operating means on the towing vehicle, andthe latter retain their equalizing connections with said fluid operatingunits regardless of whether the iiuid actuated unit connected with oneof said uid operating units is operatively connected with the fluidoperating unit on the towed vehicle for operating the brake applyingmechanism on the towed vehicle or with the cushioning reacting device318 mounted on the towing vehicle.

'Ihe fluid conduit and tension connections between the vehicles are inFigs. l to 11 inclusive shownv as a composite structure, namely, thehose 42, which serves as the 'conduit between the fluid operating unit48 on the towing vehicle and the uid actuated unit 28| on the towedvehicle, for normal brake application on the towed vehicle, and has atension connection by its physical structure between the towing vehicleand a memberof the brake operatingmeans on the towed vehicle foremergency application of vimanes on the latter on a breakaway betweenthcwenicles.

In Figs. 12 and 13 the iiuid fllhluiaand tension connections are shownas separate structures, the fluid conduit connection being shown as ahose 38|, and the tension connection being shown asa cable 382. The hose38| has fluid connection at its respective ends respectively with thecylinder of the iiuid operating unit 48 on the towing vehicle and withthe cylinder of the fluid actuated unit 28| on the towed vehicle. Thetension connection 382 has a connection 383 with the towing vehicle atone of `its ends, and a connection 384 with a brake operating member ofthe brake operating means on the towed vehicle at ,the other of itsends, this latter connection being shown as a ring on the 'plug 286 ofthe iluid actuated unit 28|, whereby, upon a breakaway, the cylinder 853of the fluid operating unit 285 is moved endwise with relation to itspiston 854, which is held against endwise movement in the same directionby the rod 285 and its contact connection with the cross rod 334.

The hitch 388 between the towing vehicle and the towed vehicle isusually vderanged or broken upon such breakaway, whereby separationtakes place between the towing vehicle and the towed vehicle. Suchseparation causes a tension strain on the tension connection, whethersuch tension connection be a separate member, as shown' by the cable882, or be the conduit hose 42, between the towing vehicle and the towedvehicle, for

causing movement of the movable member for brake application on thetowed vehicle, to thereby automatically apply the brakes on the towedvehicle, eiecting an emergency brake application f on the towed vehicle.The tension connection between the towing vehicle and the towed vehicleis severed upon excess strain being applied thereto by such separationbetween the vehicles or by increase in such separation, but theemergency brake application on the towed vehicle will al ready havetaken place prior to such severing.

The tension connection between the towing vehicle and the towed vehicle,whether it be a sepa.-

rate connection or the iuid conducting tube, is

preferably weaker than the hitch between said vehicles and issuiilciently long to avoid tension action thereon until a breakawayoccurs. iluid conduit connection and the tension connection are.preferably effectively longer than said hitch, so that, while the hitchconnects the'vehicles, said connections are unstrained between thevehicles. The tension connection becomes eiective for pulling connectionbetween the vehiclesnpon failure of the hitch between the vehicles, tomake emergency brake application on the towed vehicle upon undueseparation between the vehicles. Such greater lengths of such conduitand tension connections also insures that emergency brake application onthe towed vehicle is avoided until a failure of the hitch occurs. It isalso preferred that when a separte tension connection 882 is' employed,the conduit connection 88| is eectively longer than the tensionconnection to insure that emergency brake application on the towedvehicle takes place prior to severance in the conduit connection 38|upon breakaway between the vehicles. Said connections are preferably ofsuch length that their normal functions will not be disturbedbyrflimitedV movements between the vehicles, such as take place intravel,

whether straightaway or turning, in placing the respective vehicles. orin loading or unloadingthe same.

The brake applying means for the towing vehicle remain eiective forapplying the brakes on the towing vehicle upon a breakaway between thevehicles, due to the segregation between the iiuid conduits respectivelyon the towing vehicle and on the towed vehicle, and'to the limiting ofthe pivotal movement permitted the bar 85 on the operating rod 11. l

AWhen it is desired to apply the brakes under normal conditions, theoperator on the towing vehicle presses on the pedal ISI, which hasmechanical connections comprising the rod |34, the control valve |81,the operating rod 11, and the cross-bar 85, with the iiuid operatingunits 45, 46A, amplified by the connection of the power actuator |85with the operating rod 11, to operate the movable members of saidrespective fluid operatingy The' brake. mechanisms respectively on .the

towing vehicle and on y[the towed vehicle are each self-contained andindependent of each other for brake application, and eaclrof the samecomprises an actuated member for eiecting brake application, theactuated member on the towing vehicle-'being exempliiied as the pistonrod 8 1, and the brake applying member on the towed vehicle beingexemplified as the Voperating rod The- 285. The fluid operating unit'46,the conduit 42 and the iiuid actuated unit 28| form the brake operatingconnecting mechanism between the towing vehicle and the towed vehicle,which is normally operated on the towed vehicle and exerts its operatinginfluence on the brake mechanism of the towed vehicle, so that thebrakes on the towed vehicle are applied substantially simultaneouslywith thebrake application on the towing vehicle. This brake operatingconnecting mechanism may be entirely separate or removed, with the brakemechanism on thel towing vehicle and the brake mechanism on the towedvehicle respectively remaining intact, for independentbrake applicationon the towing vehicle'and on the towed vehicle. y

The interconnecting mechanism between the towing vehicle and the towedvehicle comprises means acting upon a breakaway between, the towingvehicle and, the towed vehicle, for emergency brake application on thetowed vehicle,

and means for maintaining brake application on the towed vehicle untilmanual or intentional control of such brake mechanism on thetowed towedvehicle thus has its brakes applied thereon, and the brakes on thetowing vehicle are' still under control of the driver on the towingvehicle,

immediately in advance of the towed vehicle, which has broken away, oron some connected vehicle in advance thereof, it being assumed that theterm towing applies to an advance vehicle in a train of vehicles, andthe term towed applies to one of the vehicles in' rear thereof. f

, vehicles.

Such emergency brake application is caused by the pulling action betweenthe vehicles to operate one of the movable members of the brakemechanism on the towed vehicle for lemergency brake application. Thismovement'is instanced as taking place between the rod 285 operating thepiston'854`and the cylinder 552 in which the same operates. In thepresent exempliilcation the rod 285 is the movable member for normalbrake application; and the cylinder' 653 is the movable member foremergency brake application, although it will be readily understood-that there may be a transposition between these parts andI movements,or that either one of these members may be. the moving member in normalbrake application or in emergency-brake application, or that any othermovable member may be employed for emergency brake application on thetowed vehicle, within the scope of my invention, as stated in theaccompanying claims.

Upon accidental separation between atowing vehicle and the towedvehicle, tension is applied to a connecting member between the vehicles,in-

, stanced as the conduit 42 in the exempliiication the brake mechanismon the towed vehicle is moved for emergency application of the brakes,and holding means are also provided, exemplied vehicle is. againassumed. Upon a breakaway the 2,5-

When now a breakaway occurs there is imme- 35 as the cams 335 forholding the movable member` in moved position in order to insurecontinuance of brake application on the towed vehicle until intentionalcontrol is again taken of the brake mechanism on the towed vehicle, asby means of the operating lever 353, and the supplemental lever 360, thelatter instanced as controlling the cam or holding member, and theformer instanced as controlling the brake application.

Accidental separation between the towing vehicle and the towed vehicletakes place by failure of the driving connection between them, for in-lstance, of the hitch 396. Immediately upon such failure, emergency brakeapplication of the brakes on the towed vehicle takes place, and onfurther separation between the vehicles upon the breakaway, partingbetween the connecting member of the emergency brake applying mechanismoperatively disposed between the vehicles, between the movable emergencybrake applying member on the towed vehicle and the towing vehicle takesplace, but the braking mechanism on the towed vehicle has already beenapplied, and such brakes are held or lockedin brake applied position bythe holding or locking means before such parting occurs.

'I'he manual control for the emergency brake application on the towedvehicle is subjected to continual tests, because it is also employed fornormal brake application on the towed vehicle. as when connecting thevehicles in a train, when placing the towed vehicle for parking, whenreassuming control of the vtowed vehicle upon a breakaway, and whenloading the towed vehicle, whether the towed vehicle be connected or notwith a towing vehicle, as it has been found advisable to apply thebrakes on the towed vehicle by the separate control therefor whenloading, so that its position on the groundi is fixedi.

The uidy operating units 45, are preferably of equal brake applyingcapacity when the brake applying members thereof are equally operated.It occurs in practice, however, in assembling dif ferent towing vehiclesand towed vehicles, that the applied forces on the brakes on thevehicles respectively differ for equal brake application. To equalizesuch dierences I have provided the relative adjustment between theoperating rod 11 and the movable members of the respective uid operatingunits l5, 46, as by adjusting thedistances between the pivot connectionsIl, Il and the pivot connection Ii, so as to adjust the length of thearms of the cross bar Il at the respective of the brake applying meansrespectively for the brake mechanism on the towing. vehicle and on thetowed vehicle other than that' herein exempliiied may coact with anoperating member of each such other brake mechanisms; that, further.aditferent character of connecting means between the towing vehicle andthe towed vehicle than the flexible connections, represented by the hoseand the cable and their connections, may be employed as the tension,pulling or actuating member between the towing vehicle and the towedvehicle for emergency brake application uponla breakaway; that, further.a different form of holding means, clamp or lock to 'hold the parts inemergency brake condition than that herein exemplified, may be employed;that the power means or medium for actuations of the brake mechanismsand the brake operating connecting mechanisms and the controls therefor,respectively, may be compressed air or fluid other than that hereinparticularly mentioned; and that other changes in structures andarrangements from what is herein shown and described may be made withoutdeparting from the spirit and scope of my invention set forth in theaccompanying claims.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent, is: y

1. In braking mechanism between a towing vehicle and a towed vehicleprovided with brake mechanism, the combination of a hydraulic operatingunit, a hydraulic operated unit for brake application on the towedvehicle, and hydraulic passage and tension connections between saidvehicles severable upon separation between said vehicles and constructedrespectively for operation of said brake mechanism on the towed vehiclelthe former by connection with said hy-v draulic units and by thehydraulic -medium in said units and in said hydraulic passage for normalbrake application of said brake mechanism on the towed vehicle and thelatter by having connection with said hydraulic operated unit foremergency brake application of said brake mechanism on the towedvehicle.

2. In braking mechanism between a. towing vehicle and a towed vehicleprovided with brake mechanism, the combination of a hydraulic operatingunit for mounting on the towing vehicle, a hydraulic operated unit forbrake application on the towed vehicle, and a hydraulic conduit betweensaid units for the hydraulic medium of said units for normal brakeapplication of said brake mechanism of the towed vehicle, and saidhydraulic conduit being connected with said hydraulic operated unit foremergency brake application of said brake mechanism on the towed vehicleinduced by tension of said hydraulic conduit upon a breakaway betweensaid vehicles.

3. In braking mechanism between a towing vehicle and a towed vehicleprovided with brake mechanism, the combination of a hydraulic operatingunit, a hydraulic operated unit for brake application on theA towedvehicle, and hydraulic passage and tension connections between saidvehicles severable by separation between said vehicles, said hydraulicpassage connection vconnectin'g said units for normal hydraulicoperation of said hydraulic operated unit for normal operation of saidbrake mechanism of said towed vehicle, and said tension connectionhaving operative connection with said hydraulic operated unit foremergency operation of said brake mechanism of the towed vehicle uponseparation between said vehicles.

4. In braking mechanism between a towing vehicle and a towed vehicleprovided with brake mechanism, a fluid operating unit on the towingvehicle, a fluid operated unit for brake application on the towedvehicle comprising a fluid actuated member and a tension actuatedmember,

'and iluid passage and tension connections between said vehiclesrespectively having passage connection with said iluid actuated memberto transmit iuid communication between said units for fluid actuation ofsaid iluid actuated member for normal operation of said brake mechanismand operative connection with said tension actuated member for operationof said brake mecha.-

nisxn by tension upon a breakaway between said vehicles.

5. In braking mechanism between a towing vehicle and a towed vehicleprovided with brake mechanism, a fiuid'operating unit for mounting onthe towing vehicle, a fluid operated unit for brake application on thetowed vehicle comprising a pair of oppositely movable members for brakeapplication, and uid passage and tension connections between said-unitsrespectively to transmit iiuid insaid fluid passage connection betweensaid units to actuate one of said movable members for normal brakeapplication of said brake mechanism on the towed vehicle and saidtension connection constructed for operation' of the other of saidmovable members upon a breakaway between said vehicles for emergencybrake application of said brake mechanism on the towedvehicle.

6. In brake connecting means between a towing vehicle and a towedlvehicle, a uid operating unit for the towing vehicle, a fluid operatedunit for the towed vehicle constructed for normal uid actuation and foremergency mechanical actuation, in order to accordingly operate thebrake mechanism on the towed vehicle, and a fluid conduit between saidunits for such normal fiuid actuation and having tension applied theretoby separation between. said vehicles for such emergency mechanicalactuation.

e 7. In braking mechanism, a master fluid pressure unitfor attachment toa towing vehicle, a fluid transfer actuator having fluid passageconnection with said' unit, a second master uid pressure unit comprisinga' normally actuated part with which said uid transfer actuator has op,erative connection for normal actuation of the same to obtain normalbrake application on a towed vehicle and a normally stationary member lhaving tension connection with the towing vehicle for moving saidnormally stationary member relatively to said normally actuated part bythe tension of said tension connection upon a breakaway between saidvehicles for emergency brake application on the towed vehicle.

i 8. In braking mechanism between towing and towed vehicles for applyingthe brakes on the towed vehicle, an operating part for normal brake.application normally operable from the towing vehicle, a stop Aforlimiting retraction of said opltowing vehicle, a stop for limitingretraction 'of said operating part, a brake actuator comprising amovable normal -brake applying ,element retractingly held by said stopand a 'eoacting normally stationary element movable for emergency brakeactuation, a partable connection between said towing vehicle and saidnormally stationary element for vmovement thereof for emergency brakeapplication upon a breakaway between said towing and towed vehicles, andholding means for said normally stationary element to hold the same inmoved. position to maintain emergency brake application. Y

1 0. In braking mechanism between towing and towed vehicles for applyingthe brakes on the towed vehicle, anoperating part for normal brakeapplication normally operable from the towing vehicle, a stop forlimiting retraction of said operating part, va brake ,actuatorcomprising a movable normal brake applying element retractingly held bysaid stop and a coacting normally stationary element movable foremergency brake actuation, a partable connection between said towingvehicle and said normally stationary element for movement thereof foremergency brake application upon a breakaway between said towing andVtowed vehicles; holding means for said normally stationary element t'ohold thel same in moved position to maintain emergencybrake application,and manual means to control said holding means and operate said normallystationary element to reassume control of brake application.

4 1l. In braking mechanism between towing and towed vehicles, thecombination of brake applying means for the brakes on the towed vehicle,an operating part therefor having connection with the towing vehicle andnormally operable therefrom, movement limiting means for said operatingpart, and mounting means. for said brake applying means having operativeconnection with the towing vehicle to move said brake applying meanswith relation to said limited movement of said operating part wherebyvto apply the brakes on the towed vehicle.

12. In braking mechanism between a towing vehicle and a towed vehicle,the combination of a fluid actuating unitv for brake application on thetowed` vehicle comprising a pair of members one of which is normallystationary and the other of which is normally movable in a givendirection for normal brake application,l a stop to `limit the retractionof said normally movable member, a partable connection between saidnormally stationary memberand the towing vehicle whereby to actuate saidnormally station- 'ary member in such retracting direction for emergencybrake application at a breakaway, and holding means to hold saidnormally stationary. member in'actuated position.

13. In braking mechanism Ybetween a ltowing vehicle and a. towedvehicle, the combination of a fluid transfer unit and a fluid actuatingunit for brake application on the towed vehicle comprising normallystationary cylinders and normally movable pistons, an actuating memberbetween said pistons normally movable in a given direction for normalbrake application, a stop to limit the retraction of saidv actuatingmember,

a -partable connection between said cylinders and the towing vehiclewhereby to actuate said cylinders in suchretracting direction foremergency brake application at a breakaway, and holding means to holdsaid cylinders in actuated positions.

14. In braking mechanism; the combination .of a guide and a slidetherefor, constituting a pair of relatively movable members, a transferunit and an operating unit each comprising a pair of Arelatively movableelements, one element of each of said pairs of elements held to one 'ofsaid pair of members and the other element of each of said pairs ofelements movable with relation thereto, and a connecting member betweenthe latter for lnormal brake application, a stop for the latter held tothe other of said pair of members, and means to move said one of saidpair of members for brake application.

15. In braking mechanism, the combination of a guide and a slidetherefor, constituting a pair of relatively movable members, a transferunit and an operating unit each comprising a pair of relatively movableelements, one element of each of said pairs of elements held to one ofsaid pair of members and the other element of each of said pairs ofelements movable `with relation thereto, and a. connecting memberbetween the latter for normal brake application, a stop for the latterheld to the other of said pair of members, means to automatically movesaid one of said pair of members for brake application upon a breakaway,and automatic maintaining means for said one of said pair of members.

16. In braking mechanism between a towing vehicle and a towed vehicle,the combination of a guide, a slide therefor, an actuating unit forbrake application on the towed vehicle comprising a normally stationarymember on said slide and a normally movable member, operating means onthe towing vehicle for said normally movable member for normal brakeapplication on the towed vehicle, normallyinactive connecting meansbetween the towing vehicle and said slide for moving said slide foremergency brake application on the towed vehicle, holding means betweensaid slide and said guide, spring means to normally hold said holdingmeans in holding relation, and manually operated spring means to releasesaid holding means.

17. In braking mechanism between a towing vehicle and a towed vehiclehaving a hitch therebetween, the combination of a fluid actuating uniton the towed vehicle for brake actuation on the latter including anormally stationary member and a normally movable member, and fluid andtension connections extending from the towing vehicle and havingoperative connections with said fluid actuating unit respectively foroperating said normally movable member for normal brake application onsaid towed vehicle and for moving said normally stationary member at abreakaway for emergency brake application on said towed vehicle, saidfluid actuating unit shiftable to said towing vehicle with said fluidand tension connections.

18. In braking mechanism between a towing vehicle and a towed vehicle,the combination of a guide, a slide therefor, a fluid transfer unit anda fluid actuating unit for brake application on the towed vehiclecomprising normally stationary cylinders secured to said slide andnormally movable pistons, an actuating member between said pistonsnormally movable in a given direction for normal brake application, astop to limit retraction of said actuating member, and a connectionbetween said slide and the towing vehicle whereby to actuate said slidein such retracting direction for emergency brake application at abreakaway.

19. In braking mechanism between a towing vehicle and a towedvvehicle,the combination of a guide, a slide therefor, a fluid transfer unit anda fluid actuating unit for brake application on the towed vehiclecomprising normally stationary cylinders secured to said slide andnormally movable pistons, an actuating member between said pistonsnormally movable in a given direction fo: normal brake application, astop to limit the retraction of said actuating member, a partableconnection between said slide and the towing vehicle whereby to actuatesaid slide in such retracting direction for emergency brake applicationat a breakaway, and holding means to hold said slide in actuatedposition.

20. In braking mechanism between a towing vehicle and a towed vehicle,the combination of a guide, a slide therefor, a fluid transfer unit anda fluid actuating unit for brake application on the towed vehiclecomprising normally stationary cylinders secured to said slide andnormally movable pistons, an actuating member betweenl said pistonsnormally movable in a given direction for normal brake application, astop to limit the retraction of said actuating member, a partableconnection between said slide and the towing vehicle whereby to actuateVsaid slide in such retracting direction for emergency brake applicationat a breakaway, holding means to hold said slide in actuated position,and manual control means for said holding means and said slide for brakeapplication on the towed vehicle.

21. In braking mechanism between a towing vehicle and a towed vehicleeach of which has braking means and fluid brake applying means for thelatter thereon. the brake applying forces in said respective brakeapplying means being related for related pressures in said respectivebraking means, the combination of a fluid transfer unit normally locatedon the towed vehicle and comprising a fluid actuated member having anormal movement and meeting a normal resistance in normal brakeapplication on the towed vehicle, an actuating unit for the latter onthe towing vehicle, fluid conduit connection between the latter and saidfluid actuated member, and means on the towing vehicle to position saidfluid transfer unit including a resiliently yieldable resistance deviceconstructed for movement and resistance respectively similar to saidnormal movement and said normal resistance to cushioningly resistactuation of said fluid actuated member for maintaining the brakeapplying pressure in the fluid brake applying means on the towingvehicle.

22. In brake applying means for a plurality of brake mechanisms, a fluidoperating unit for each of `said brake mechanisms, each of said` fluidoperating units comprising an operating part, a common operating memberfor said operating parts, a cross bar having jointed connection withsaid operating member to form actuating arms extending from saidoperating member and for tilting movements of said cross bar on saidoperating member, means between said operating member and said cross barto limit such tilting movements, said cross bar having jointedconnections with said respective operating parts, and adjusting means torelativelyadjust the distances between said jointed connections to varythe lengths of said actuating arms.

23. In brake applying means fora plurality of brake mechanisms, a fluidoperating unit for each of said brake mechanisms, each of said fluidoperating units comprising an operating part, a pair of supports, saidfluid operating units mounted on one of said supports, a commonoperating member for said operating parts and operating means thereforon the other oi' said supports. a cross bar having jointed connectionswith said operating member and with each of said operating parts,adjusting means to relatively adjust thedistances between said jointedconnections, and means for relative ad- 7| justment between saidsupports to accommodate for adjustments of said last-named adjusting'means. y

24. In brake applying means for a plurality of brake mechanisms, a pairof supports, a uid operating unit for each of said brake mecha-1 nismsmounted on one of said supports, each of said uid operating unitscomprising an' operating part, a manual operating member, a cross barhaving jointed connections with said operating and means for relativeadjustment between said i supports to accommodate for said adjustmentsbetween said jointed connections.

25. The combination with towing and towed trackless vehicleshaving ahitch therebetween.

said towed vehicle provided with self-contained braking mechanism, of amovable brake applying member for said self-contained braking mechanism,an emergency brake applying connection between said movable brakeapplying member and the towing vehicle operable upon a breakaway toactuate said movable brake applyingmimber for emergency'brakeapplication of said self-contained braking mechanism on said towedvehicle, and automatic holding means to automatically hold said movablebrake applying member in actuated position.

26. The combination with towing and towed trackless vehicles having ahitch connection therebetween, said towedvehicle provided withself-contained braking mechanism, of brake applying means for lsaidself-contained braking mechanism, said brake applying means comprising aplurality of members having relative movement between them for brakeapplication on Vsaid towed vehicle, and passage and pull conneccation ofsaid self-contained braking m and operable upon a breakaway between saidvehicles to apply the brakes on the towed vehicle.

Y21. The combination with towing and towed trackless vehicles having ahitch connection therebetween, said towed vehicle provided withself-contained braking mechanism, o! brake ap-` plying means for saidself-contained braking mechanism, said brake applying means comprising aplurality of members having relative movement between them for brakeapplication on said towed vehicle, and pull connections operavelyconnected with the towing vehicle, said e connection having operativeconnection with amember vof said plurality of members for normal brakeapplying movement between said members i'or normal. brake application ofsaid self-contained braking mechammandsaid pullccnnectionhavlngoperative conneclionwith'amemberofsaidpluralityotmembers for emergency brake applying movement between said members foremergency brake application of said self-contained braking mechanism andoperable upon a breakaway between said vehicles to apply the brakes onthe towed vehicle, and automatic holding means to hold said last-namedmember of said plurality of members in emergency brake applyingrelation.

28. The combination with towing and towed trackless Veh-icles having ahitch connection therebetween, said towed vehicle provided withself-contained braking mechanism, of brake applying means for saidself-contained braking mechanism, said brake applying means comprisingaplurality of members having relative movement between them for brakeapplication on said towed vehicle, passage and pull connectionoperatively connected with the towing vehicle, said passage connectionhaving operative connection with a member of said plurality of membersfor normal brake applying movement between said members for normal brakeapplication of said self-contained braking mechanism, and said pullconnection having operative connection with a member of said pluralityof members for emergency brake applying movement-between said membersfor emergency brake application of said self-contained braking mechanismand operable upon a breakaway between said vehicles to apply the brakeson the towed vehicle, and automatic holding means to hold saidlast-named member of lsaid plurality of membersin emergency brakeapplying relation, and said hitch connection and said pull connectionbeing constructed to be partable in the order named upo a breakawaybetween said vehicles.

29. In braking mechanism between a towing vehicle and a towed vehicleprovided with brake mechanism, the combination of a uid operating unitfor mounting on the towing vehicle, a fluid operated unit for brakeapplication on the towed vehicle comprising a pair of members for brakeapplication, and iiuid passage and tension connections between said umtsrespectively to transmit iluid in said iiuid passage connection between'saidunits'to actuate one of said members of said fluid operated unit fornormal brake application of -said brake mechanism on the towed vehicleand said tension connection constructed for operation, of one' of saidmembers of saidliiuid operated unit upon a breakawaybebrake mechanism onthe towed mechanism, the combination, of ahydraulic op- 1 erating unit,a hydraulic actuated unit 4for .brake application von the towed vehicle,and anchor members-coacting with said brake mech'- anism on the towedvehiclegami` hydraulic passage andte'rision` connections between said:vehicles, said Vhydraulic passage having operative connectionwith thesaidj'hydraulic -tween said vehiclel for emergencybrake applil actuatedunit for'actuationofsaidactuating member for normal brake applicationvoffsaid` brake mechanism on'the towed vehicle and-said tension connectionhaving `fwith A'said ofsaid brake on thejtcwedvehicle upon a breakawaybetween said vehicles.vv

'- anchormember for 70 v wAIiI'm-li. Panna

